git-commit-vandalism/Documentation/git-rev-list.txt

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git-rev-list(1)
===============
NAME
----
git-rev-list - Lists commit objects in reverse chronological order
SYNOPSIS
--------
'git-rev-list' [ *--max-count*=number ] [ *--max-age*=timestamp ] [ *--min-age*=timestamp ] [ *--bisect* ] [ *--pretty* ] [ *--objects* ] [ *--merge-order* [ *--show-breaks* ] ] <commit> [ <commit> ...] [ ^<commit> ...]
DESCRIPTION
-----------
Lists commit objects in reverse chronological order starting at the
given commit(s), taking ancestry relationship into account. This is
useful to produce human-readable log output.
Commits which are stated with a preceding '^' cause listing to stop at
that point. Their parents are implied. "git-rev-list foo bar ^baz" thus
means "list all the commits which are included in 'foo' and 'bar', but
not in 'baz'".
OPTIONS
-------
--pretty::
Print the contents of the commit changesets in human-readable form.
--objects::
Print the object IDs of any object referenced by the listed commits.
'git-rev-list --objects foo ^bar' thus means "send me all object IDs
which I need to download if I have the commit object 'bar', but
not 'foo'".
--bisect::
Limit output to the one commit object which is roughly halfway
between the included and excluded commits. Thus, if 'git-rev-list
--bisect foo ^bar ^baz' outputs 'midpoint', the output
of 'git-rev-list foo ^midpoint' and 'git-rev-list midpoint
^bar ^baz' would be of roughly the same length. Finding the change
which introduces a regression is thus reduced to a binary search:
repeatedly generate and test new 'midpoint's until the commit chain
is of length one.
--merge-order::
When specified the commit history is decomposed into a unique
sequence of minimal, non-linear epochs and maximal, linear epochs.
Non-linear epochs are then linearised by sorting them into merge
order, which is described below.
+
Maximal, linear epochs correspond to periods of sequential development.
Minimal, non-linear epochs correspond to periods of divergent development
followed by a converging merge. The theory of epochs is described in more
detail at
link:http://blackcubes.dyndns.org/epoch/[http://blackcubes.dyndns.org/epoch/].
+
The merge order for a non-linear epoch is defined as a linearisation for which
the following invariants are true:
+
1. if a commit P is reachable from commit N, commit P sorts after commit N
in the linearised list.
2. if Pi and Pj are any two parents of a merge M (with i < j), then any
commit N, such that N is reachable from Pj but not reachable from Pi,
sorts before all commits reachable from Pi.
+
Invariant 1 states that later commits appear before earlier commits they are
derived from.
+
Invariant 2 states that commits unique to "later" parents in a merge, appear
before all commits from "earlier" parents of a merge.
--show-breaks::
Each item of the list is output with a 2-character prefix consisting
of one of: (|), (^), (=) followed by a space.
+
Commits marked with (=) represent the boundaries of minimal, non-linear epochs
and correspond either to the start of a period of divergent development or to
the end of such a period.
+
Commits marked with (|) are direct parents of commits immediately preceding
the marked commit in the list.
+
Commits marked with (^) are not parents of the immediately preceding commit.
These "breaks" represent necessary discontinuities implied by trying to
represent an arbtirary DAG in a linear form.
+
[PATCH] Modify git-rev-list to linearise the commit history in merge order. This patch linearises the GIT commit history graph into merge order which is defined by invariants specified in Documentation/git-rev-list.txt. The linearisation produced by this patch is superior in an objective sense to that produced by the existing git-rev-list implementation in that the linearisation produced is guaranteed to have the minimum number of discontinuities, where a discontinuity is defined as an adjacent pair of commits in the output list which are not related in a direct child-parent relationship. With this patch a graph like this: a4 --- | \ \ | b4 | |/ | | a3 | | | | | a2 | | | | c3 | | | | | c2 | b3 | | | /| | b2 | | | c1 | | / | b1 a1 | | | a0 | | / root Sorts like this: = a4 | c3 | c2 | c1 ^ b4 | b3 | b2 | b1 ^ a3 | a2 | a1 | a0 = root Instead of this: = a4 | c3 ^ b4 | a3 ^ c2 ^ b3 ^ a2 ^ b2 ^ c1 ^ a1 ^ b1 ^ a0 = root A test script, t/t6000-rev-list.sh, includes a test which demonstrates that the linearisation produced by --merge-order has less discontinuities than the linearisation produced by git-rev-list without the --merge-order flag specified. To see this, do the following: cd t ./t6000-rev-list.sh cd trash cat actual-default-order cat actual-merge-order The existing behaviour of git-rev-list is preserved, by default. To obtain the modified behaviour, specify --merge-order or --merge-order --show-breaks on the command line. This version of the patch has been tested on the git repository and also on the linux-2.6 repository and has reasonable performance on both - ~50-100% slower than the original algorithm. This version of the patch has incorporated a functional equivalent of the Linus' output limiting algorithm into the merge-order algorithm itself. This operates per the notes associated with Linus' commit 337cb3fb8da45f10fe9a0c3cf571600f55ead2ce. This version has incorporated Linus' feedback regarding proposed changes to rev-list.c. (see: [PATCH] Factor out filtering in rev-list.c) This version has improved the way sort_first_epoch marks commits as uninteresting. For more details about this change, refer to Documentation/git-rev-list.txt and http://blackcubes.dyndns.org/epoch/. Signed-off-by: Jon Seymour <jon.seymour@gmail.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06 17:39:40 +02:00
*--show-breaks* is only valid if *--merge-order* is also specified.
Author
------
Written by Linus Torvalds <torvalds@osdl.org>
[PATCH] Modify git-rev-list to linearise the commit history in merge order. This patch linearises the GIT commit history graph into merge order which is defined by invariants specified in Documentation/git-rev-list.txt. The linearisation produced by this patch is superior in an objective sense to that produced by the existing git-rev-list implementation in that the linearisation produced is guaranteed to have the minimum number of discontinuities, where a discontinuity is defined as an adjacent pair of commits in the output list which are not related in a direct child-parent relationship. With this patch a graph like this: a4 --- | \ \ | b4 | |/ | | a3 | | | | | a2 | | | | c3 | | | | | c2 | b3 | | | /| | b2 | | | c1 | | / | b1 a1 | | | a0 | | / root Sorts like this: = a4 | c3 | c2 | c1 ^ b4 | b3 | b2 | b1 ^ a3 | a2 | a1 | a0 = root Instead of this: = a4 | c3 ^ b4 | a3 ^ c2 ^ b3 ^ a2 ^ b2 ^ c1 ^ a1 ^ b1 ^ a0 = root A test script, t/t6000-rev-list.sh, includes a test which demonstrates that the linearisation produced by --merge-order has less discontinuities than the linearisation produced by git-rev-list without the --merge-order flag specified. To see this, do the following: cd t ./t6000-rev-list.sh cd trash cat actual-default-order cat actual-merge-order The existing behaviour of git-rev-list is preserved, by default. To obtain the modified behaviour, specify --merge-order or --merge-order --show-breaks on the command line. This version of the patch has been tested on the git repository and also on the linux-2.6 repository and has reasonable performance on both - ~50-100% slower than the original algorithm. This version of the patch has incorporated a functional equivalent of the Linus' output limiting algorithm into the merge-order algorithm itself. This operates per the notes associated with Linus' commit 337cb3fb8da45f10fe9a0c3cf571600f55ead2ce. This version has incorporated Linus' feedback regarding proposed changes to rev-list.c. (see: [PATCH] Factor out filtering in rev-list.c) This version has improved the way sort_first_epoch marks commits as uninteresting. For more details about this change, refer to Documentation/git-rev-list.txt and http://blackcubes.dyndns.org/epoch/. Signed-off-by: Jon Seymour <jon.seymour@gmail.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06 17:39:40 +02:00
Original *--merge-order* logic by Jon Seymour <jon.seymour@gmail.com>
Documentation
--------------
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
GIT
---
Part of the gitlink:git[7] suite